CodeWF.EventBus
CodeWF.EventBus 是一个轻量的进程内事件总线库，适合在 WPF、WinForms、Avalonia UI、ASP.NET Core 和控制台程序中做模块解耦。它支持 Command 命令分发，也支持 Query<T> 查询回传，便于实现简单 CQRS。
Suitable for the scene
- Desktop application modules do not want to directly reference each other's services or ViewModels.
- ASP.NET Core wants to split the controller, service processor, and query logic with a lightweight event bus.
- The Console, WinForms, WPF, or Avalonia projects do not have a unified IOC container, but still want to use subscription publishing to decouple the process.
- 希望比
MediatR更小、更少框架约束，同时保留 Command/Query 思路。
package selection
| package | applicable scenarios |
|---|---|
CodeWF.EventBus |
No IOC containers or manual subscriptions. |
CodeWF.AspNetCore.EventBus |
ASP.NET Core / MS.DI。 |
CodeWF.DryIoc.EventBus |
DryIoc / Prism。 |
CodeWF.IOC.EventBus |
Other IOC containers access registration and resolution capabilities through callbacks. |
core type
public abstract class Command
{
}
public abstract class Query<TResponse> : Command
{
public abstract TResponse Result { get; set; }
}
Example:
public sealed class CreateProductCommand : Command
{
public string Name { get; set; } = string.Empty;
public decimal Price { get; set; }
}
public sealed class ProductQuery : Query<ProductItemDto?>
{
public Guid ProductId { get; set; }
public override ProductItemDto? Result { get; set; }
}
processor writing
事件处理方法使用 [EventHandler] 标记，参数只能有一个，且必须继承自 Command。返回值支持 void 和 Task，方法可以是 public、private 或 static。
[Event]
public sealed class ProductEventHandler
{
[EventHandler]
private async Task HandleCreateAsync(CreateProductCommand command)
{
await Task.CompletedTask;
}
[EventHandler(Order = 1)]
private void HandleQuery(ProductQuery query)
{
query.Result = new ProductItemDto
{
Id = query.ProductId,
Name = "Demo",
Price = 99
};
}
}
No IOC containers
public sealed class MainViewModel
{
private readonly IEventBus _eventBus = EventBus.Default;
public MainViewModel()
{
_eventBus.Subscribe(this);
}
[EventHandler]
private void Handle(UpdateTimeCommand command)
{
Console.WriteLine(command.Time);
}
}
Issue orders and inquiries:
await EventBus.Default.PublishAsync(new CreateProductCommand
{
Name = "XiaoMi",
Price = 8999
});
var product = await EventBus.Default.QueryAsync(new ProductQuery
{
ProductId = Guid.NewGuid()
});
When an instance object is no longer in use, it is recommended to proactively unsubscribe:
EventBus.Default.Unsubscribe(this);
ASP.NET Core
using CodeWF.AspNetCore.EventBus;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers();
builder.Services.AddEventBus();
var app = builder.Build();
app.MapControllers();
app.UseEventBus();
app.Run();
AddEventBus() 会扫描程序集中的 [Event] 类并注册到容器中，UseEventBus() 会把扫描得到的处理器接入事件总线。